This invention relates to an inductance device which is used in for example a noise filter for an alternating current (AC) line.
When an inductance device is used in high frequency region, inter-wire capacitance of the coil might have a detrimental effect on noise filtering property of the inductance device. To suppress the inter-wire capacitance effect, JP 1997-102426 A, JP 2004-311866 A or JP 2004-235709 A has proposed a magnetic core that is grounded, those documents being incorporated herein by reference.
However, the grounding of the magnetic core decreases design flexibility of the inductance device.